One thing libraries have a lot of is books. Don’t get me wrong, they also have a lot of other things—programs, services, databases, meeting rooms. . . I could go on and on. But we still have lots of books.

At one point in time libraries had a lot of what we call “reference books”—things like dictionaries, encyclopedias, directories, atlases, gazetteers, and the like. Nowadays, not so many reference books (although they still have some!), because so much of what we used them for can now be found online.